Hb C-Harlem beta6(A3)Glu->Val;
HEMATOLOGY Normal in the heterozygote
ELECTROPHORESIS Hb X moves like Hb C in standard electrophoresis at alkaline pH; at acidic pH (agar gel) Hb X occupies the position of Hb S
CHROMATOGRAPHY Hb X elutes with Hb A2 in anion exchange chromatography; Hb X also separates from Hb A on a CM-Sephadex column
STRUCTURE STUDIES Tryptic digestion of AE-betaX chain; separation of peptides by fingerprinting; amino acid analysis; sequencing
DNA ANALYSES Not reported; presumed mutations GAG->GTG and GAT->AAT at codons 6 and 73
STABILITY Hb X is less stable than Hb A and Hb S
OCCURRENCE Found in several (10-15) Black families
OTHER INFORMATION Quantity in the heterozygote 40-44%; sickling when deoxygenated; when found together with Hb S the condition resembles sickle cell anemia; insoluble in concentrated phosphate; gels at higher concentrations than Hb S; the beta73 Asp->Asn replacement is characteristic for Hb Korle- Bu
1. Bookchin, R.M., Nagel, R.L., and Ranney, H.M.: J. Biol. Chem., 242:248, 1967.
2. Nagel, R.L. and Bookchin, R.M.: Nature, 241:143, 1973.
3. Moo-Penn, W.F., Bechtel, K., Jue, D., Chan, M.S., Hopkins, G., Schneider, N.J., Wright, J., and Schmidt, R.M.: Blood, 46:363, 1975.

This material is from the book A Syllabus of Human Hemoglobin Variants (1996) by Titus H.J. Huisman, Marianne F.H. Carver, and Georgi D. Efremov, published by The Sickle Cell Anemia Foundation in Augusta, GA, USA. Copyright © 1996 by Titus H.J. Huisman. All rights reserved. Neither this work nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, microfilming and recording, or by any information storage and retrieval systems, without written permission.